Footwear article

ABSTRACT

The footwear article comprises a generally elongate sole having a first portion for interaction with a ground surface during ambulation, a second portion for interaction with the ground surface during ambulation, and a third portion between the upper surface and the lower surface. The first portion includes a first material with a first material property, the second portion includes a second material with a material property, and the third portion includes a material with a third material property. The first and portions extend to the upper surface of the sole. The first material property provides dampening of impact load imparted to the foot of the person upon contact of the footwear article with the ground surface. The third material property is a visco-elastic property for providing controlled deformation upon contact of the footwear article with the ground surface and returns to an initial state upon removal of the impact.

FIELD OF THE INVENTION

The present invention relates to the field of footwear articles, inparticular to footwear of composite form.

BACKGROUND OF THE INVENTION

It is well known in the art that shock loadings and forces applied tothe underside of the foot of a person via the sole of footwear articlehave long term effects on the integrity of joints of a person, whilstalso at times causing pain and discomfort, in particular when wearingfootwear for extended periods of time.

Furthermore, it is well known that the majority of loading on impact tothe foot of a person is imparted to the underside of the heel portion ofthe foot of a person in use.

Footwear articles of the prior art include various manners in which toincrease comfort and conformity to the foot of user, including shockabsorptive inserts, various types of foam rubber and air cushioningdevices. Such footwear articles typically require increasedmanufacturing costs and tooling, thus increasing complexity ofproduction.

The present invention is provides a footwear article which overcomes orat least substantially ameliorates at least some of the deficiencies asexhibited by those of the prior art.

SUMMARY OF THE INVENTION

In a first aspect, the present invention provides a footwear articlecomprising:

a generally elongate sole for engagement with and support of the foot ofa person, said sole having an upper surface, a lower surface, a firstportion being for interaction with at least the heel region of the footof the person, a second portion for interaction with at least a groundsurface during ambulation, and a third portion disposed between theupper surface and the lower surface; and

a foot engagement means for securing the footwear article to the foot ofa person.

characterised in that a first portion of the sole includes a firstmaterial having a first material property, the a second portion of thesole includes a second material having a second material property, andthe third portion of the sole includes a third material having a thirdmaterial property,

said first portion and said second portion extend at least to the uppersurface of the sole, the first material property provideing fordampening of impact load imparted to the foot of the person upon contactof the footwear article with a ground surface, and the third materialproperty being a visco-elastic property for providing controlleddeformation upon contact of the footwear article with a ground surfaceand return to an initial state upon removal of said impact.

The third portion may extend substantially the length of the sole andsubstantially the width of the sole.

The visco-elastic property of the third portion may be non-uniformlaterally. The visco-elastic property material of the central portion ofthe third portion may deform in a manner greater than the medial andlateral portions of the third portion so as to oppose lateral movementof the foot of the person with respect to the sole during ambulation.

The visco-elastic property of the third portion is non-uniformlongitudinally.

Preferably, the second portion provides for interaction with at leastthe metatarsal region of the foot of the person.

Preferably the first portion further provides for interaction with andat least partial support of the plantar arch of the user.

Preferably the first portion extends substantially laterally across thesole.

Alternatively, the first portion is provided as a first part and asecond part and laterally spaced apart such that the first part providesfor interaction with the lateral inferior of the heel of the person andthe second part provides for interaction with the medial inferior aspectof the heel of the user. The first part and the second part of the firstportion are preferably sized and selected from a material so as toprovide lateral stabilisation and load distribution of the heel of theperson.

The first material property and the second material property may differfrom each other and the first material and the second material maydiffer from each other, and the first material and the second materialhave differing densities.

The first portion and the second portion are preferably selected fromthe group including polymeric materials, rubbers, elastomers and organicmaterials or combinations thereof.

Preferably the first material and the second material are selected fromthe group including thermoplastic polymeric material, co-polymers andmixed polymer blends.

The first material and the second material are preferably selected fromthe group including polyurethane, ethylene vinyl acetate, poly vinylacetate and the like.

The first material and the second material may be provided in the formof expanded form, compact form or gel form of combinations thereof.

Preferably the first material is a polyurethane gel and the secondmaterial is an expanded poly vinyl acetate material.

Preferably, the first material is a polyurethane gel and the secondmaterial is an expanded polyurethane.

Preferably the third portion is provided as a shape memory expandedpolymer and the viscosity of and density is selected such that the thirdportion in conjunction with the third material property provides saidvisco-elastic property. Preferably the third material is polyurethane.

The third portion may be provided in the form of interconnecteddeformable sub-portions. Alternatively, the third portion may beprovided in the form of discrete deformable sub-portions.

Preferably, the third portion is provided as an expanded shape memorysponge construct.

Preferably, the sub-portions have a geometry which is partiallyspherical.

The engagement means is preferably selected from the group includingstraps, an enclosure, a buckle or the like.

Preferably the sole is formed as a unitary construct by co-molding thefirst portion and the second portion, with the third portionencapsulated within the sole. The sole is preferably formed as a unitaryconstruct whereby the first portion and the second portion are joinedtogether by an adhesive bonding agent, contact cement pressure or heatactivated film or the like.

The upper surface of the sole is preferably provided as a substantiallycontinuous surface and formed by at least part of the first portion andthe second portion of the sole, and the first portion preferably extendspartially towards the lower surface of the sole. Alternatively, thefirst portion may extend through the sole to the lower surface of thesole.

The upper surface is preferably of concave form and the sole includes aperipheral lip extending at least partially along the periphery of thesole so as to provide a contoured upper surface configured to receivethe underside of the foot of the person.

The first portion of the sole may be provided as a multi-layered gelconstruct.

The sole may further include a fourth portion which extends to the uppersurface of the sole and having material property provides for dampeningof load imparted to the foot of the person upon contact with a surface,said third portion providing for interaction with at least themetatarsal region of the foot of the person.

Preferably the footwear article is provided is substantiallynon-enclosed, more preferably in the form of a “flip-flop” type footweararticle. Alternatively, the article may be provided in the form of a“sandal” type footwear article, or as an at least partially enclosedfootwear article.

Alternatively, the article may be provided as a heeled article such thatthe upper surface of the sole is inclined in a direction of from theupper surface towards the lower surface in a direction of from the firstportion towards the second portion, and the third portion is located ina portion to substantially prevent or reduce movement of the foot of theperson along the upper surface of the sole. The fourth portion may belocated so as to be at adjacent the ball of the underside of the foot ofthe person.

Preferably, said first material is a gel type polymeric material andsaid second material is an expanded polymeric material, the sole ispreferably formed as a unitary molded structure, and said first portionand said second portion co-operatively form a flexible sole.

Preferably a part of the first portion and a part of the second portionform the upper surface of the sole.

In a second aspect, the present invention provides a footwear articlecomprising:

a generally elongate sole comprising a first portion, a second portionand a third portion and having an upper surface and a lower surface,

said first portion being for direct contact and interaction with atleast a portion of the underside of the foot of the person and beingformed from a first polymeric material having a first density;

said second portion forming substantially the entire lower surface ofthe footwear article and being for direct contact and interaction with aground surface and being formed from a second polymeric material havinga second density; and

said third portion being disposed between the upper surface and thelower surface, and being formed from a third polymeric material, whereinsaid third

a generally elongate and flexible foot engagement means for securing thefootwear article to the foot of a person, said foot engagement beingengaged directly with at least said second portion and configured so asto extend over a portion of the upper side of the foot of the person;

wherein the first polymeric material and the second polymeric materialare selected and the first portion and the second portion are sized andarranged such that the sole is substantially flexible and elastic so asto allow for substantial flexion of the sole longitudinally and return,when in use and during ambulation of the person;

wherein the first polymeric material and the second polymeric materialare selected and the first portion and the second portion are sized andarranged such that dampening is provided upon load being imparted to thefoot of the person upon contact with the surface;

wherein the third material property is a visco-elastic property forproviding controlled deformation upon contact of the footwear articlewith a ground surface and return to an initial state upon removal ofsaid impact; and

wherein the sole is formed as a unitary construct by co-molding thefirst portion and the second portion together with the third portionencapsulated within the sole, and the first polymeric material and thesecond polymeric material are suitably selected for said co-molding.

The first density is preferably greater than the second density, and thefirst material is preferably provided in a gel form and the secondpolymeric material is preferably provided in an expanded form.

In a preferred embodiment, the foot engagement means is a “thong” typeengagement means, and the footwear article is provided in the form of a“flip-flop” type footwear article.

The third portion may extend substantially the length of the sole andsubstantially the width of the sole.

The visco-elastic property of the third portion is non-uniform laterallyor non-uniform longitudinally.

The visco-elastic property of the central portion of the third portionmay deform in a manner greater than the medial and lateral portions ofthe third portion so as to oppose lateral movement of the foot of theperson with respect to the sole during ambulation. The first polymericmaterial and the second polymeric material may be selected from thegroup including thermoplastic polymeric materials, co-polymers and mixedpolymer blends, more preferably from the group including polyurethane,ethylene vinyl acetate, poly vinyl acetate and the like.

In a preferred embodiment, the first material is a polyurethane gelmaterial and the second material is an expanded polyurethane material.

The third portion may be provided as a shape memory expanded polymer andthe viscosity of and density is selected such that the third portion inconjunction with the third material property provides said visco-elasticproperty. Preferably, the third material is polyurethane.

The third portion may be provided in the form of interconnecteddeformable sub-portions. Alternatively, the third portion may beprovided in the form of discrete deformable sub-portions.

Preferably, the third portion is provided as an expanded shape memorysponge construct.

Preferably, the sub-portions have a geometry which is partiallyspherical.

The first portion may extend substantially laterally across uppersurface of the sole and substantially form the rear part of the uppersurface of the sole, and the second portion may form at least a part ofthe front part of the upper surface of the sole.

Alternatively, the first portion may form at least part of the frontpart of the upper surface of the sole, and the second portion may format least a part of the rear part of the upper surface of the sole.

In an alternate embodiment, the first portion may form substantially theentire upper surface of the sole

The first portion may further provide for interaction with and at leastpartial support of the plantar arch of the user.

In other embodiments, the first portion may be provided as a first partand a second part and laterally spaced apart such that the first partprovides for interaction with the lateral inferior of the metatarsalregion of the foot of the person and the second part provides forinteraction with the medial inferior aspect of the metatarsal region ofthe foot of the person. The first part and the second part of the firstportion may be sized and selected from a material so as to providelateral stabilisation and load distribution of the heel of the person.

In further embodiments, the upper surface may be of concave form and thesole may include a peripheral lip extending at least partially along theperiphery of the sole so as to provide a contoured upper surfaceconfigured to receive the underside of the foot of the person.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention will be explained infurther detail below by way of examples and with reference to theaccompanying drawings, in which:

FIG. 1 a is a plan view of an exemplary embodiment of a footwear articleaccording to the present invention;

FIG. 1 b is a side view of the embodiment of the invention as depictedin FIG. 1 a;

FIG. 1 c is an enlarged side view of a portion of the embodiment ofFIGS. 1 a and 1 b, in a partially deconstructed arrangement;

FIG. 1 d depicts the embodiment of the footwear article of FIG. 1 a in aflexed state;

FIG. 2 a shows an exemplary embodiment of a third portion of the articleaccording to the present invention;

FIG. 2 b shows a cross-sectional view through the embodiment of FIG. 2 athrough the line E-E;

FIG. 2 c shows a further exemplary embodiment of a third portion of thearticle according to the present invention;

FIG. 2 d shows a cross-sectional view through the embodiment of FIG. 2 cthrough the line F-F.

FIG. 3 a depicts a cross-sectional view of a first schematicrepresentation of a footwear article according to the present invention;

FIG. 3 b depicts a cross-sectional view of a second schematicrepresentation of a footwear article according to the present invention;

FIG. 3 c depicts a cross-sectional view of a third schematicrepresentation of a footwear article according to the present invention;

FIG. 3 d depicts a cross-sectional view of a fourth schematicrepresentation of a footwear article according to the present invention;

FIG. 3 e depicts a cross-sectional view of a fifth schematicrepresentation of a footwear article according to the present invention;

FIG. 3 f depicts a cross-sectional view of a sixth schematicrepresentation of a footwear article according to the present invention;

FIG. 3 g depicts a cross-sectional view of a seventh schematicrepresentation of a footwear article according to the present invention;

FIG. 3 h depicts a cross-sectional view of the first schematicrepresentation of the footwear article of the present invention alongthe line A-A;

FIG. 3 i depicts a cross-sectional view of the third schematicrepresentation of the footwear article of the present invention alongthe line B-B;

FIG. 3 j depicts a cross-sectional view of the second schematicrepresentation of the footwear article of the present invention alongthe line C-C;

FIG. 3 k depicts a cross-sectional view of the seventh schematicrepresentation of the footwear article of the present invention alongthe line D-D;

FIG. 4 a is a plan view of another exemplary embodiment of a footweararticle according to the present invention;

FIG. 4 b is an underside view of the embodiment of the invention asdepicted in FIG. 4 a;

FIG. 4 c is a side view of the embodiment of the invention as depictedin FIGS. 4 a and 4 b;

FIG. 5 a is a plan view of another schematic representation of anembodiment of the present invention;

FIG. 5 b is a plan view of a further second schematic representation ofan embodiment of the present invention;

FIG. 5 c is a plan view of yet another schematic representation of anembodiment of the present invention;

FIG. 5 d is a plan view of yet a further schematic representation of anembodiment of the present invention;

FIG. 6 a is a plan view of a first schematic representation of yetanother embodiment of the present invention;

FIG. 6 b is a plan view of a second schematic representation of yet afurther embodiment of the present invention;

FIG. 6 c is a plan view of a third schematic representation of still afurther embodiment of the present invention;

FIG. 7 a depicts yet still another embodiment of a footwear articleaccording to the present invention;

FIG. 7 b depicts yet still a further embodiment of a footwear articleaccording to the present invention;

FIG. 8 depicts an alternate embodiment of a footwear article accordingto the present invention; and

FIG. 9 depicts yet an alternate embodiment of a footwear articleaccording to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 a to 1 d show an exemplary embodiment of a footweararticle 100 according to the present invention is shown. In the presentembodiment, the footwear article 100 is provided in the form of a“flip-flop” type article, however other articles or other or alternateembodiments are also applicable to the invention, such as a sandal,slip-on type shoes or the like.

The article 100 is provided as a generally elongate sole 110 which, inthe present invention, is provided as three portions, a first portion116, a second portion 118, and a third portion 115 disposed between thefirst portion and the second portion although those skilled in the artwill appreciate that the article 100 may be provided as further portionswithout departing from the invention.

A foot engagement means 120 is provided which is provided so as toco-operatively secure the article 100 to the foot of a person. Althoughdepicted as a typical “flip flop” engagement device, those skilled inthe art shall appreciate that other engagement devices such as straps,buckles, cross-overs or the like are equally applicable to theinvention. Co-operatively with the sole 110, the engagement means 120secures the article 100 to the foot of a person.

The engagement means 120 is affixed to the sole 110 of the article viaapertures extending through the sole 110, the engagement means 120having formations for abutting against and within recesses within theunderside 114 of the sole 110. Again, those skilled in the art willunderstand that various engagement means may secured to the sole 110 inother manners where applicable.

The first portion 116 is positioned and formed from a material suitablefor providing cushioning or dampening to the heel of a person whenstanding or during walking. The second portion 118 provides for supportof the front portion or metatarsal portion of the foot of a person.

The third portion 115 has visco-elastic properties for providingcontrolled deformation upon contact of the footwear article with aground surface and return to an initial state upon removal of saidimpact.

The first portion 116 of the sole 110 is formed from a gel-typepolymeric material, in the present embodiment a polyurethane gelmaterial, which provides for cushioning and shock absorption to the heelportion of a user.

The second portion 118 of the sole 110 is formed from a furtherpolymeric material, in the present embodiment expanded polyurethane,which is integrally formed with the first portion 110. The secondportion of the present embodiment forms the majority of the sole, theflexural properties in conjunction with suitable sizing provides forsignificant flexing of the sole when walking and again increases comfortto a use.

In the present embodiment 100, the third portion 115 extendssubstantially the length of the sole and substantially the width of thesole. However, as will be appreciated by those skilled in the art, inother or alternate embodiment, the visco-elastic property of the thirdportion is non-uniform laterally and may vary laterally.

For example, the visco-elastic property of the central portion of thethird portion may deform in a manner greater than the medial and lateralportions of the third portion so as to oppose lateral movement of thefoot of the person with respect to the sole during ambulation.

This can provide a degree of assistance in preventing or at least partlyameliorating the incidence of a person walking off the medial or lateralside of the footwear article. This may provide advantages orthoticallyas well as provide more even distribution of wear of the heel portion ofthe article, hence increasing and enhancing product longevity. As willalso be appreciated, third portion and hence visco-elastic propertiesmay be non-uniform longitudinally, depending upon the physicalrequirements of the article.

In a preferred embodiment such as that of the present embodiment, thethird portion is provided as a shape memory expanded polymer and theviscosity of and density is selected such that the third portion inconjunction with the third material property provides said visco-elasticproperty. preferably, the third material is polyurethane.

In the present embodiment of the article 100, the first portion 116 andthe second portion 118 are integrally formed by a co-molding process,whilst the third portion 115 is located within the mold so as to beencapsulated within the sole 110 of the article 100.

Further, such a co-molding process so as to provide continuity betweenthe portions 116 and 118, and results in an interphase between the firstportion 116 and the second portion 118, rather than an interface. Such aprocess of formation provides a suitably strengthed bond between thefirst portion 116 and the second portion 118.

A co-molding process, as will readily be understood by those skilled inthe art, is whereby the portions are molded together and are generallyformed with a common mold.

By being formed as a co-molded sole 110, the present invention providesfor continuity of the sole 110 to be formed as a unitary construct,allowing for ease of form and providing for continuity of the uppersurface 112 of the sole, thus allowing for direct contact of theunderside of the foot of a user and also provides for ease of formationand manufacturing. Further, by providing a unitary construct such thatthe sole 110 is substantially formed in total by the first portion 116and the second portion 118, ease and simplicity of formation andmanufacture is achieved.

In other or alternate embodiments, the sole 110 may be formed byadhering the first portion 116 and the second portion 118 together byadhesives, pressure or heat sensitive glues or the like, whereapplicable.

Although in the present embodiment, the first portion 116, the secondportion 118 are formed from a polyurethane gel, an expanded polyurethanematerial and a shape memory polyurethane visco-elastic material,respectively, those skilled in the art that other polymer orthermoplastic materials may also be utilised, such as poly vinyl acetatematerials or other such suitable polymeric materials.

Alternatively, in other embodiments and as would be understood by thoseskilled in the art, other materials such as rubbers, elastomers, organicmaterials or combinations thereof, and co-polymer and mixed polymerblends and combinations thereof may also be utilised. Further, materialsmay be provided in the form of compact polymers, expanded polymericmaterials or gel materials or combinations thereof and may be used invarious combinations without departing from the scope of the invention.Furthermore, the sole 110 may be provided as a single material havingvarying densities so as to provide a first portion with appropriatecushioning whilst being of a expanded form for example for other partsof the sole so as to provide for structural integrity.

In other embodiments, cushioning elements such as “air cushioning”elements may be incorporated within the sole to provide for additionalcushioning to the foot of a user.

Referring to FIG. 2 a and FIG. 2 b, Referring to FIGS. 2 a-2 d, thereare shown schematic exemplary embodiments of a third portion 200 a, 200b, in accordance with the present invention. The third portion 200 a,200 b may be provided as a polymeric sheet, or any other membrane withsuitable visco-elastic deformable portions 210 a, 210 b, which, asdepicted, are interconnected by a membrane 220 a, 220 b.

As will be appreciated by those skilled in the art, numerous embodimentsand materials or constructs may be applicable, to provide thevisco-elastic properties in accordance with the requirements for thethird portion 200 a, 200 b, in accordance with the present invention.

Preferably, the third portion 200 a, 200 b, is provided as an expandedshape memory sponge type construct, for example, an expandedpolyurethane material. Again, those skilled in the art will appreciatethat any similar such suitable material for providing the requisitevisco-elastic properties is equally as applicable to the presentinvention.

Referring to FIGS. 3 a-3 g, there are shown cross-sectional schematicviews of a number of alternate exemplary embodiments of a footweararticle 300 a-300 g according to the present invention, theseembodiments 300 a-300 g include a third portion 310 a-310 g being formedof different geometries depending upon the particular requirements andrequisite physical properties of the article 300 a-300 g.

As will be noted and appreciated by those skilled in the art, the thirdportions 300 a-300 g may be of different geometries, sizes and shapes,and may extend both laterally and longitudinally in different amount soas to provide different visco-elastic dampening, again depending uponthe application of the article.

Referring to FIGS. 3 h-3 k cross-sectional views are shown in which thethird portions 310 a, 310 c, 310 b and 310 g are depicted as beingencapsulated within the footwear article 300 a, 300 c, 300 b and 300 g.

Referring to FIGS. 4 a-4 c, there is shown another exemplary embodimentof a footwear article according to the present invention. In thisembodiment, the sole 410 is provided with a concave upper surface 412which is suitably contoured so as to provide for comfort of fit to thefoot of a user when wearing the article 400. A peripheral lip 413 isprovided which extends around the periphery of the sole 410 againproviding for comfort to a user and for foot conformity.

In the present embodiment, the first portion 416 further extends as amedial portion 419 to provide arch support to the foot of a person.Those skilled in the art will appreciate that other geometries andpositioning of the first portion 416 may be provided in other oralternate embodiments so as to provide cushioning to the underside ofthe foot of a person, without departing from the scope of the invention.

Referring to FIGS. 5 a-5 d, there are shown schematic representations ofembodiments of the present invention. Referring to FIG. 5 a there isshown an embodiment 500 a of the invention whereby a fourth portion 515a is provided towards the metacarpal portion of a user's foot to providefor cushioning to the front portion of the foot of a user. The fourthportion may be formed from same of different materials as that of thefirst portion 516 a.

In another embodiment of the footwear article 500 b as shown in FIG. 5b, the first portion 516 b and the second portion 515 b are integrallyformed, and co-operatively provide for lateral support of the undersideof the foot of a user.

Referring to FIG. 5 c, and embodiment of the footwear article 200 c isshown whereby a portion 519 c of the first portion provides for medialarch support.

In a further embodiment of a footwear article 500 d according to thepresent invention as depicted in FIG. 5 d, the first portion 516 d isprovided as two separate parts being spaced apart laterally so as toprovide for increased medial or lateral support and cushioning to theunderside of the heel portion of the foot of a user.

Referring to FIGS. 6 a, 6 b and 6 c, there are shown embodiments offootwear articles 600 a, 600 b and 600 c having various foot engagementmeans. FIG. 6 a shows a foot engagement means 620 typical of that of a“flip-flop”, FIG. 6 b shows an “cross-over” type engagement means andFIG. 6 c shows a single-strap type foot engagement means 620 c. Thoseskilled in the art will appreciate that numerous types of footengagement means are applicable without departing from the scope of theinvention.

Referring to FIG. 7 a, there is shown another embodiment of a footweararticle 700 according to the present invention. In the presentembodiment, the first portion 710 extends along the entire length of thearticle 700 so as to provide the entire upper surface 720. In thisembodiment, the first portion 710 again is formed from a gel material soas to provide dampening to the foot of a user upon impact, incombination with an expanded polymeric foam of which the second portion720 is formed.

Further, in the present embodiment, elongate grooves 740 extendlaterally across the upper surface 720 of the article 700. The grooves740 allow for localized deformation of the first portion 710, whichprovides for additional dampening to the foot of a user during use.Furthermore, the laterally extending grooves 4740 also provide a “grip”effect which prevents slippage of the foot of a user against the othersurface 720 during use.

Referring to FIG. 7 b, there is shown a further embodiment of a footweararticle 700 according to the present invention. Similarly as in theembodiment depicted in FIG. 7 a, the first portion 710 extends theentire length of the footwear article 700 so as to form the entire uppersurface 720. Again, the second portion is provided by an expandedpolymeric material 720 of foam form which extends the entire length ofthe article 700.

In the present embodiment, grooves 740 are provided which, similarly asin the embodiment depicted in FIG. 7 a, allow for localized deformationof the first portion 710, and due to the gel like properties, andfurther incorporation with the expanded polymeric properties of thesecond portion 730, the grooves 740 allow for additional dampening andcushioning to the foot of a user during use. Furthermore, again thegrooves 740 provide a “grip” type effect which reduces slippage of thefoot of a user on the upper surface 720 of the article 700 during use.

Referring now to FIG. 8, there is depicted yet a further embodiment of afootwear article 800 according to the present invention. In the presentembodiment, the first portion 810, again formed from a gel material, andin this embodiment is provided towards the front portion of the footweararticle 800. The first portion 810 forms a part of the upper surface820, and the second portion 830, again formed from an expanded polymericmaterial, forms the remaining portion of the upper surface 820.

In the present embodiment, the first portion 810 provides for dampeningand shock absorption at the front portion of the foot of a user in use,and furthermore, the first portion being located in this positionprovides for grip of the foot of a user and prevents slippage along theupper surface 820 in use.

Referring now to FIG. 9, there is depicted yet a further embodiment of afootwear article 900 according to the present invention. In the presentembodiment, the first portion 910 is provided again in a gel materialform, and the second portion 930 is provided in an expanded polymericform. The first portion 910 extends the entire length of the footweararticle 900 so as to form the entire upper surface 920 of the article900

In reference to the embodiments of the invention as described in thedescription above, as will be appreciated by those skilled in the art,the footwear articles are provided such that the sole of the articlecomprises the entire sole of the device, and the foot engagement meansmerely hold the sole to the bottom of the foot of the user. Suchfootwear articles are termed different names in different parts of theworld, including terms such as “flip flop”, “thongs” and “jandals”.

As will be understood by those skilled in the art, to provide aflip-flop type footwear article, the article must be extremely flexibleso as to allow for continual flexing during walking or ambulation of aperson. Such a sole is distinctly different from that of traditionalfootwear articles, whereby a comparatively small amount of flexion isallowable and typically at one portion of the sole, in comparison withthat as required and provided by flip-flop type footwear articles.

As will also be appreciated by those skilled in the art, it is necessaryto provide an article which, after many repetitions of flexion,maintains its structural integrity without the first portion and thesecond portion separating or delaminating.

Furthermore, those skilled in the art will appreciate that the sole of aflip-flop device as claimed and shown in the accompanying drawings inaccordance with the present invention, only comprises the upper portionand the lower portion as described, the upper portion (i.e. firstportion) providing for direct contact with the underside of the foot ofa user most often without a sock, and the lower portion (i.e. secondportion) engages directly with the grounds or surface upon which aperson walks, without the use of additional outer source or the like.

Furthermore, flip-flop type footwear, as will readily be understood andappreciated by those skilled in the art, are often exposed to harshenvironmental conditions such as water and long durations of sunlightdue to their typical applications, and the materials from which they areformed and the manner in which the portions are joined, must be capableof withstanding such exposure.

As such, those skilled in the art will appreciate that a substantialdifference exists between the sole of the footwear article in thepresent invention and those of conventional footwear, for which have inthe prior art been described as being formed by multiple layers.

It will be appreciated, that as the sole of the present invention iscomprised only of the first portion and the second portion, theseportions must be securely joined or bonded together securely in amanner, as there exists no outer shoe body whereby an inner sole isstill retained within a shoe even if not securely bonded to the insideof a shoe, and also in view of typical applications as discussed above.

The present invention has overcome problems of the prior art such asdelamination, so as to provide a footwear article having a soledistinctly different from those of conventional footwear, a sole whichmust endure significantly larger amounts of flexion and strain, whilstmaintaining the structural integrity of the sole. By provision of a“co-molding process” whereby a gel material is co-moulded with apolymeric material which is expanded in a manner so as to providecontinuity between the gel-type material and the expanded polymericmaterial. As such, a unitary sole of a unitary construct has beenprovided that overcomes practical and longevity problems which may beencountered when utilizing bonding techniques such as used in the priorart. The co-molding process provides for structural integrity and alsomaintains the bond between the materials throughout angles of flexion ofthe sole well beyond the amount of flexion that conventional footwearare exposed to.

Furthermore, the co-molding process simplifies production so as to allowease of manufacture and reduction in manual labour, and does not requireseparate formation of the two portions, and does not require apost-fabrication process for joining the portions.

Thus, the two portions, by being moulded, provides a unitary structurewhereby the sole is formed of a “continuous” polymeric material, withoutthe necessity for adhesive and the like, and thus mitigating theincidence of de-bonding, even throughout repetitive large amounts offlexing. The co-molding process provides for rapid and cost and timeeffective manufacture, and reduces the amount of material wastage, thusalso providing environmental advantages.

While the present invention has been explained by reference to theexamples or preferred embodiments described above, it will beappreciated that those are examples to assist understanding of thepresent invention and are not meant to be restrictive. Variations ormodifications which are obvious or trivial to persons skilled in theart, as well as improvements made thereon, should be considered asequivalents of this invention.

Furthermore, while the present invention has been explained by referenceto “flip-flop” type footwear articles, it should be appreciated that theinvention can apply, whether with or without modification, to otherfootwear articles without loss of generality.

1-70. (canceled)
 71. A footwear article comprising: a generally elongatesole comprising a first portion, a second portion and a third portionand having an upper surface and a lower surface, said first portionbeing for direct contact and interaction with at least a portion of theunderside of the foot of the person and being formed from a firstpolymeric material having a first density; said second portion formingsubstantially the entire lower surface of the footwear article and beingfor direct contact and interaction with a ground surface and beingformed from a second polymeric material having a second density; saidthird portion being disposed between the upper surface and the lowersurface, and being formed from a third polymeric material, a generallyelongate and flexible foot engagement means for securing the footweararticle to the foot of a person, said foot engagement being engageddirectly with at least said second portion and configured so as toextend over a portion of the upper side of the foot of the person;wherein the first material is provided in a gel form and the secondpolymeric material is provided in an expanded form, and wherein thefirst density is greater than the second density; wherein the firstpolymeric material and the second polymeric material are selected andthe first portion and the second portion are sized and arranged suchthat the sole is substantially flexible and elastic so as to allow forsubstantial flexion of the sole longitudinally and return, when in useand during ambulation of the person; wherein the first polymericmaterial and the second polymeric material are selected and the firstportion and the second portion are sized and arranged such thatdampening is provided upon load being imparted to the foot of the personupon contact with the surface; and wherein the third material propertyis a visco-elastic property for providing controlled deformation uponcontact of the footwear article with a ground surface and return to aninitial state upon removal of said impact.
 72. A footwear articleaccording to claim 71, wherein the first portion forms substantially theentire upper surface of the sole.
 73. A footwear article according toclaim 71, wherein the third portion is provided as a shape memoryexpanded polymer and the viscosity of and density is selected such thatthe third portion in conjunction with the third material propertyprovides said visco-elastic property.
 74. A footwear article accordingto claim 71, wherein the third portion is provided in the form ofinterconnected deformable sub-portions or discrete deformablesub-portions.
 75. A footwear article according to claim 71, wherein thethird portion is provided as an expanded shape memory sponge construct.76. A footwear article according to claim 74, wherein the sub-portions ageometry which is partially spherical.
 77. A footwear article accordingto claim 71, wherein the third portion extends substantially the lengthof the sole and substantially the width of the sole.
 78. A footweararticle according to claim 71, wherein the visco-elastic property of thethird portion is non-uniform laterally.
 79. A footwear article accordingto claim 71, wherein the visco-elastic property of the third portion isnon-uniform longitudinally.
 80. A footwear article according to claim71, wherein the first polymeric material and the second polymericmaterial are selected from the group including thermoplastic polymericmaterials, co-polymers and mixed polymer blends.
 81. A footwear articleaccording to claim 71, wherein first polymeric material and the secondpolymeric material are selected from the group including polyurethane,ethylene vinyl acetate, poly vinyl acetate and the like.
 82. A footweararticle according to claim 71, wherein the third polymeric material ispolyurethane.
 83. A footwear article according to claim 71, wherein saidfoot engagement means is selected from the group including straps, anenclosure, a buckle or the like.
 84. A footwear article according toclaim 71, wherein the sole is formed as a unitary construct byco-molding the first portion and the second portion together, with thethird portion encapsulated within the sole.
 85. A footwear articleaccording to claim 71, wherein said foot engagement means is a “thong”type engagement means, and the footwear article is provided in the formof a “flip-flop” type footwear article.